Types: Lunette
Lunette are a particular subset of portali; these decorative arches span the tops of doorways and serve both a structural and aesthetic purpose. In Italian, lunetta essentially means "half-moon," describing the decoration’s semicircular shape. Lunette typically surround artwork from a number of artistic mediums, styles, and themes. There are three prominent styles of lunette in Venice: Byzantine, Gothic, and Renaissance. Byzantine lunette date back to the 12th century and are distinguished by their dome shape and religious themes. Gothic lunette, popular between the 12th and 15th centuries, are characterized by pointed arches, which are generally larger and contain more elaborate detail than other styles. During the 15th and 16th centuries, Renaissance lunette appeared, with more elegant decorations and simpler subjects, such as the sole image of a saint or the Madonna.
Just as there are various styles of lunette, there are also a variety of materials and techniques used in their construction. 
Fifty-one percent of the lunette in Venice are made of Istrian stone, 24 percent are marble, 12 percent brick, seven percent tile, four percent paint, and two percent wood or metal. Istrian stone was a popular choice, because it is durable and relatively non-porous, allowing sculptures to endure in the damp Venetian climate. Besides the differences in materials, Venetian lunette also exhibit a variety of artistic techniques and media. The most popular is relief, accounting for 78 percent of all lunette, followed by 11 percent mosaic, seven percent sculpture, and four percent fresco.
There are 71 lunette in Venice; Cannaregio and Castello contain the greatest number, at 22 percent each. Most lunette are found on palazzi and churches because, in general, only wealthy families and institutions could afford them. Forty-five percent of all lunette can be found in residential areas and 23 percent on churches, monasteries, or convents. The remaining 23 percent of lunette are located in commercial areas.
Click here to go to the list of types of public art.